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[rob meldrum]

Hi all,  After 12 months of waiting for our
new house to be built, we're moving in next
month.  I am now re-testing all my X10
paraphernalia.  The CM15A RF range with the
keychain remote was 15 feet.  Ugh.  I did
the range mod, but used an inexpensive
dipole antenna from Radio Shack (the wire
in a clear sheath, in a "T" used for FM
reception in lots of stereos) and now I
have reliable RF reception from the
keychain remote in my entire 4000 sq ft
house, plus from the driveway.  Amazing.
Looking forward to setting up and testing
motion sensors, dimmers, etc.  Now that
this is fixed, the next big issue is making
sure the X10 signals are getting through.
Need to add a phase coupler and
X10 "filters."  Will keep you posted on
progress.
Rob

[Brian H]

OH Yes the mod does make things work so much
better. We will stay tuned for future
updates and questions.

[roger1818]

Rob:  Did you change the length of the of
the dipole antenna?  Also, did you use a
matching transformer?  Does anyone know
what impedance the CM15A is expecting to
see?

[Brian H]

Schematic for the receiver isn't much help
[says 240mm for lenght] as is the receiver
chip makers refference design show the
impedance. The WGL v572 that uses a simmilar
receiver module comes with RG6 cable that is
75 ohms but that isn't 100% on what X10s
uses. Thank goodness receivers are more
forgiving than transmitters. When I tested
my modified cm15a I used the WGL supplied
one. I have also seen a message on the
accessha.com forum where someone got better
distance just by uncoiling the extra antenna
wire inside the cm15a and putting a longer
hollow tube in place of the shorter one on
the side with the wire fully extended.

[bob linca]

Rob Meldrum,

What is the part number for the antenna that
you used, and how did you connect it to the
CM15A?

Thanks,

Bob

[rob meldrum]

Glad someone is interested!  Radio Shack FM
dipole antenna:
http://www.radioshack.com/product.asp?
catalog%5Fname=CTLG&product%5Fid=42-2385
First I tried straightening out the
internal antenna, got *maybe* an extra
three feet of coverage, and this is in an
open area, no walls, range died at fifteen
feet with regular unit, maybe two-three
more feet with antenna extended.  The
antenna mod is described here in other
threads, but the link is:
http://www.accessha.com/howto_fconnector_pag
e1.html
I did *not* make a coax connection, as I am
a novice at messing with electronics.  I
soldered in a ground wire per the link, cut
the antenna wire, and soldered each to a
female spade connector.  I used a glue gun
to glue the two wires firmly to the box
where the old antenna connected.  I mounted
the dipole antenna on a wall, with
the "arms" of the antenna at right angles.
Plug the CM15A in to the dipole antenna
with the spade connectors, and suddenly the
weak keychain remote works everywhere in
the house.  PalmPad remote works great,
too.  I was very pleased at how easy this
mod was.  In about three weeks we'll be
moving in and I'll have more to report.
Feel free to ask if I can be of help!
Rob

[rob meldrum]

Roger,
I did not change the antenna in any way.
I'm too electronically illiterate to know
about impedance or transformers.  I did try
using lengths of coat hangers first (some
random web site suggested that), but they
didn't help at all.  I'm about to order a
phase coupler to connect at the 220-volt
dryer.  I think I'll order an active
bridge, does that make sense to you?

Rob

[roger1818]

Rob:  Thanks for the info.  It makes me
wonder if that isn't a better approach than
using an F connector.  When the warrantee
expires on my unit in December, I will have
to do a similar mod.

With regards to the phase coupler, I highly
recommend getting one.  Check out a
tutorial I wrote at:
http://www.x10.webhop.org/Phase_Coupling.htm

One word of caution though, if you are
using a CM15A, I would stay away from the
Smarthome and Leviton (and probably X10 Pro
since the Leviton is made by X10) brands of
Coupler/Repeaters (their passive couplers
are fine).  People on here have reported
that when used with a CM15A a flood
of “Status Request” signals will start
being sent that prevent other commands from
being transmitted.  The ACT brand
coupler/repeaters apparently don’t have
this problem.

I suspect it is a bug in the CM15A and not
the coupler/repeater (in a separate thread
I theorized a cause of this problem), but
regardless of the exact cause it is best to
avoid these combinations.

[sparky]

HI
having trouble with remotes
communicating.the seem to only some of the
time.added phase coupler.i like te idea of
the ant mod.how can i do this? thanks

[sparky]

HI
having trouble with remotes
communicating.the seem to only some of the
time.added phase coupler.i like te idea of
the ant mod.how can i do this? thanks

[JimC]

Sparky,

Go to the following web site and click on
projects. you will find the antenna mod
there.
http://www.accessha.com/index.html

[Brian H]

Only update for that mod is. If you have a
later unit. The extra antenna wire maybe
glued to the case in a loop and not balled
up in a mess like my early one was.

[Brian H]

Correction. The transmitting antenna is
glued to the cover. In my later one the
extra length of the receiving one was glued
in a 'U' shape to the main board between the
receiving and transmitting daughter cards.

[michael ferguson]

Roger said: The ACT brand  coupler/repeaters apparently
don’t have this problem.

I'm sorry to report that I have two new ACT CR234 units
here that both exhibit the signal storm within 1 hour of
plugging them in...

michael

[john t.]

I understand that the SmartHome USB
controller 1132UCP doesn't have the rf range
problem exhibited by the CM15A. Anyone know
if that is the case???

John